A blind patient is able to "see" again thanks to a microchip in his
eye which beams images of Braille directly to his brain.

Wireless signals are picked up by a receiver in the white of the man's eye and transmitted to an array of electrodes attached to the surface of his retina.

The electrodes then stimulate nerve cells in order to relay the Braille patterns to the man's brain, exactly as if he were seeing them with his eyes.

The study is the first to stream Braille directly into a patient's retina, and could offer hope to thousands of people with conditions like retinitis pigmentosa, where light-sensing cells in the retina die causing partial or total blindness.

It builds on technology already licensed in the UK which uses a camera mounted on a pair of glasses to send basic light patterns to an eye implant, enabling patients to see rough outlines of objects like doorways.

Instead of using a camera researchers transmitted Braille patterns directly to the implant for greater accuracy, and they reduced the array of 60 electrodes to just six – one for each "dot" which form letters in Braille.

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The patient was able to correctly visualise Braille letters from the electric signals 89 per cent of the time, and the vast majority of errors happened when he misread just one dot, researchers reported.

Thomas Lauritzen, who led the study, explained: "We bypassed the camera that is the usual input for the implant and directly stimulated the retina.

"Instead of feeling the Braille on the tips of his fingers, the patient could see the patterns we projected and then read individual letters in less than a second with up to 89 per cent accuracy."

The patient was also able to read eight of ten two-letter words, six of ten three-letter words and seven of ten four-letter words beamed to him via the device.

Writing in the Frontiers in Neuroprosthetics journal, developers from Second Sight Medical Products said their existing camera-based implant, known as Argus II, could easily be adapted to include letter recognition software which would allow users to "see" text in Braille form.

Existing eye implants can allow patients to recognise normal text, but only in large fonts, at very close distances and taking tens of seconds to interpret each letter, meaning words can take minutes to read.

Signposts, for example, would be virtually impossible to read in plain text even with an implant, but could be made quick and simple to read if translated by the device into Braille, the researchers said.

Patients would have to be taught to read Braille visually, rather than by touch, but this would not prove too challenging for most people, they added.

Pete Osborne, chief Braille officer at the Royal National Institute of Blind People, said: "If you treat Braille as a code, then it is simpler because it removes some of the variability of print.

"What they have realised is that if you use Braille, you can have an electrode stimulus based around the six dots which make up the Braille cell and you can translate that message into the brain.

"Anything like this that has the potential to get some people back the visual realisation they have lost is a good thing, and I hope they are able to validate their study with more people."